Need to lower standover height

[eltee]

I have the Perry's Power Bike M1 Pro Mountain with the Bafang Ultra. All good.

It has 27.5 wheels, etc. which is fine for me in casual pants, riding pants, etc. but for patrolling in my uniform BDU pants the top bar and the front of the seat sometimes makes contact or "catches" me. The crotch on my duty pants hangs lower, etc.

I was wondering if going to a 26" wheel would help. I know it's only 1.5" difference and when translated to actual lowering of the top bar is even less but to make this bike work for patrol I need to lower it somehow or grow taller. Is there a way to lower the suspension?

This bike will be mainly used for streets and maintained park trails and dirt roads. Any advice appreciated. Thank you. Yes, I am a newbie.

[Drum]

Yes, 26" wheels and / or smaller section tires would lower the crossbar a bit. If the tires were the same width, the difference would be maybe 3/4" (around 20mm). Quite an expensive operation for a small difference.
Maybe find a second-hand pair of 26" wheels and put thin tires on.. use the 26 wheels for patrolling, and the 27.5's for weekend fun?

Remember that if you lower the bike, the pedals and chainring will be closer to the ground. More chance of pedal strike when cornering or on rough ground, and more chance of hitting the chainring when dropping off a ledge or riding over a log etc.
If mainly used on flat / even ground, may not be too much of an issue.

Do you already have the seatpost adjusted all the way down?

[leo99]

Hi,
I don't seem to see why changing the the wheel size would change the problem since even if you change the wheel size the seat will stay at the same height compared to the top pedals since the distance between the seat and the pedals will stay the same. Your whole bike will be lower but the frame distances will stay the same.

Good luck

[amberwolf]

Since standover height is when standing on the ground, not the pedals, it *will* change the problem, if not fix it completely.


@OP: If it has rear suspension, you could change to a shorter shock, but this will lessen the amount of travel you get. Similarly, you can change a front suspension fork to a different shorter-travel one.

If you don't change the front and rear height equally, it'll affect the handling of the bike; whether it makes it better or worse depends on which end is now taller and whether it was designed optimally to start with.

[KINNINVIEKID]

Wear high heels

[billvon]

I was wondering if going to a 26" wheel would help. I know it's only 1.5" difference and when translated to actual lowering of the top bar is even less but to make this bike work for patrol I need to lower it somehow or grow taller. Is there a way to lower the suspension?

Not much. A 26 rim is 22" in diameter and a 27.5 rim is 23" in diameter. So you only gain half an inch (since radius is 1/2 diameter) for a lot of $$.

You are probably better off:

1) Tilting the seat forward more (to prevent catching)
2) Changing the seat to one that has a smaller thickness (rails to seat surface)
3) Changing the seatpost to one that allows a lower setting

[AHicks]

It's the outside diameter of the tire that makes the difference in stand over height. Rim size may or may not be that big a deal. For instance, the difference in diameter from an off road 29'er tire to a 26" road tire could possibly be more than 3 inches.

And we're talking about stand over height. The height of the bar in front of the seat, from the ground to the top of that tube. Adjusting the seat post isn't going to change that one bit!

[spinningmagnets]

26 inch wheels will help, but not as much as you would like. It's true that there is a 1.5 inch difference from a 27.5, but...it only lowers the axle 0.75 inch.

[2old]

Probably I don't understand the problem, but if your pants are caught between the top tube and the seat can't you just put a barrier there? Maybe a chunk of foam or ??? will prevent the problem.

[billvon]

It's the outside diameter of the tire that makes the difference in stand over height. Rim size may or may not be that big a deal. For instance, the difference in diameter from an off road 29'er tire to a 26" road tire could possibly be more than 3 inches.

Right. You can get thinner tires. But if you just change from 27.5 to 26 inch wheels and keep the tire thickness the same, you are gaining only .5 inches.

And we're talking about stand over height. The height of the bar in front of the seat, from the ground to the top of that tube. Adjusting the seat post isn't going to change that one bit!

The OP said this:

"It has 27.5 wheels, etc. which is fine for me in casual pants, riding pants, etc. but for patrolling in my uniform BDU pants the top bar and the front of the seat sometimes makes contact or "catches" me. The crotch on my duty pants hangs lower, etc."

If it's a problem "catching" the front of the seat, then lowering the saddle will help. I've had a similar problem.

[Hillhater]

Probably cheaper and simpler to just get your uniform pants re tailored to prevent the problem !

[TOLM]

https://m.ebay.com/itm/ISM-Sport-Comfor ... SwNkJaAlIM

[TOLM]

Or even this

https://m.ebay.com/itm/sellOttO-Sporty- ... SwI2xbVJO2

[DingusMcGee]

Eltee,

1. Simply cut off the seat tube top that stands above the top tube. Make it as flat to the top tube that can be achieved without sacrificing the structural integrity of the joint below.

2. Get a seat post that adds the least height in its clamp-to-the-seat location.

3. To prevent the seat post from rotating drill and bolt the seat post to the seat tube a few inches below the joint of the top tube and seat post.

4. If you still want to have you feet closer to the ground convert to 26" wheels.

5. If the pedals hit too often you can cut off inches on your crank arms and rethread some new holes for the pedals -- they are mostly for standing on.

[eltee]

The seat post had an inch and 1/2 cut off the bottom so it sits lower. When you are wearing 15 lbs of stuff on your belt in loose fitting BDU pants your crotch is much lower than when riding normally. The lowered seat helped a little and I still get leg extension.

The issue is standover clearance above the top tube. I know each mod is incremental but a 1/4 inch here and 3/4 inch there all adds up. Going to talk to my local bike store guy to look into:
- Offset shock bushings
- Conversion to 26" wheels
- Adjusting sag to lower bike height
- Remounting fork stem higher into frame

This bike isn't for really hard off roading so I can sacrifice some performance for lower height. Other than the clearance issue, the bike is a blast to ride.

[nfmisso]

I went to: https://www.perryspowerbikes.com/product-p/m1-ppb.htm for information.

The specs say you have 27.5 x 2.5 tires; convert to ETRTO to make the math possible 63-584 (width and BSD). Your tires have an outer diameter of approximately 710 mm (27.9 inches).

If you switched to 559 (26") wheels with 50-559 tires; diameter would be 659 mm (25.9"); radius change is 25.5 mm (1") = the lowering of the top tube. You may want to consider 40-559 tires for an extra 10mm drop.

26" MTB disc wheel sets start at around $100- and go up, figure another $100- for tires and tubes, you can get new brake discs or re-use the ones you have (use clean nitrile gloves when touching the discs to prevent finger oil contamination).

These wheels are really nice: http://www.velocityusa.com/product/whee ... n-wheelset for your purposes Cliffhanger rims will work well. Velocity rims are my favorite; I have never purchased or used a Velocity wheelset.

[ScooterMan101]

A Selle SMP saddle will help with the catching of the pants problem, and depending on which model you buy will help make your everyday ride more comfortable.

https://www.sellesmp.com/en/saddles/tourism.html

A Dropper Post will help with the standover height problem in the following way ...

When coming to a stop drop the post, after you start riding again raise the post to the proper height .

[E-geezer]

Yep, dropper post, problem solved.